Patent document 1 discloses an A/D converter array. An A/D converter circuit of the A/D converter array includes two capacitors and an inverting amplifier. A DA converter part of the A/D converter circuit provides any of three values (VRM, VRP, and GND) to one of the capacitors.
Patent document 2 discloses a cyclic A/D converter. This cyclic A/D converter includes two pairs of capacitors, and an amplifier having a differential input and a differential output. A DA converter part of the A/D converter provides any of three values (VRM, VRP, and Common) to a pair of capacitors.
Patent document 3 discloses a highly accurate cyclic A/D converter. This A/D converter includes three capacitors and a differential-input operational amplifier. A DA converter part of the A/D converter provides any of three values (+VR, −VR, and GND) for predetermined one of the three capacitors.
Patent document 4 discloses a cyclic A/D converter. This A/D converter includes two pairs of capacitors and an amplifier having a differential input and a differential output. A DA converter part of the A/D converter provides any of three values (+Vref1, −Vref2, and COMMON) to a pair of capacitors.
Patent document 5 discloses an N-bit A/D converter. This converter includes two pairs of capacitors and an operational amplifier circuit. A DA converter circuit of the A/D converter provides any of three values (+VR, −VR, and GND) to a pair of capacitors.
Patent document 6 discloses an analog-digital converter. This analog-digital converter includes four capacitors and an operational amplifier circuit. A DA converter circuit of the A/D converter provides any of three values (VREFP, VREFN, and COMMON) to a pair of the capacitors.
Patent document 7 discloses an A/D convertor. This A/D converter includes two capacitors and an operational amplifier circuit. A DA converter circuit of the A/D converter provides any of three values (VRM, VRP, and COMMON) to a pair of the capacitors.